Cleaning the grill is nobody's favorite task, but a thorough cleaning should be done at least once per year. Just before closing it up for winter is probably the best time as it will deter tiny creatures from making it their luxury apartment.
Before you start anything, disconnect the gas from the grill. (Turning it off is not the same as disconnecting.) If you have a propane tank, take the entire thing off and move it away from the grill.
Remove all the grill parts except the burners. This includes the grate and the flavorizer bars (or the burner protection covers) that are in the shape of an upside-down ‘v’. You will also want to remove the drip tray and lava rock. You can clean lava rock, but it is best to replace them annually as they absorb a lot of grease and are difficult to clean.
Now that everything is removed, you can clean inside the hood and main compartment of the grill with soapy water. (Dawn dish soap as it is a great de-greaser and easy on the hands.) Don’t, however, use a pressure washer as this can force grease and soap residue into the burner holes. It will also make a huge mess around your cleaning area. Rinse off the soap well.
It is best not to remove the burner unless the manufacturer directions tell you to do so. Instead, use a cotton swap and/or tooth pick to clean the burner holes. Try not to let the gunk go into the holes.
Cleaning the grate and flavorizer bars is supposedly the hardest part of cleaning a grill. But fear not -- there is an easy way. Get a large heavy-duty trash bag and place the grate and bars into the bag. Add one cup of ammonia, close the bag tightly (a rubber band works great) and let the bag and contents sit overnight. The next day, open the bag carefully in a well-ventilated area, preferably outside. Make sure to keep your head away from the bag when you open it -- the fumes released from the bag will burn your nose and eyes. Remove the grate and bars. If the ammonia did its job you should be able to wipe the bars clean easily.
Rinse the grate and bars with clean water. Reassemble the grill.
Clean the outside of the grill with a soft cloth and a clean bucket of soapy water. If your grill is stainless steel, then polish it with stainless steel cleaner.
Once everything is back in its place, light the grill and let it burn for about 15 minutes. This will get off any soap residue and also ensure that the igniter is still working.
If you don’t have room in a garage or shed, the best protection for your grill over the long cold months is a good cover. Measure your grill length, height and width -- you will want one that fits perfectly. If it's too big the wind will blow it away. If its too tight, it won’t go over the grill, or if you force it the finish will be wrecked. Place your covered grill in a wind and snow protected area even when covered.
Tips and Tricks
One of the things I hate about cleaning a grill is removing the drip pan because I usually spill it and it smells atrocious. A fantastic trick for drip trays is to line them with aluminum foil and then add about a cup of kitty litter. The litter absorbs the grease, so there is no liquid to spill. When the litter stops absorbing, simply wrap up the litter in the aluminum foil, toss and replace.
Don’t skimp on a grill brush -- always use one made of stainless steel. Brass brushes have a tendency to lose their bristles and can get into your food. If accidentally eaten, the bristles can get lodged in your throat or swallowed and cause serious damage.